Internet Engineering Task Force (IETF) V. Dolmatov, Ed.
Request for Comments: 5933 A. Chuprina
Category: Standards Track I. Ustinov
ISSN: 2070-1721 Cryptocom Ltd.
July 2010
Use of GOST Signature Algorithms in DNSKEY
and RRSIG Resource Records for DNSSEC
Abstract
This document describes how to produce digital signatures and hash
functions using the GOST R 34.10-2001 and GOST R 34.11-94 algorithms
for DNSKEY, RRSIG, and DS resource records, for use in the Domain
Name System Security Extensions (DNSSEC).
Status of This Memo
This is an Internet Standards Track document.
This document is a product of the Internet Engineering Task Force
(IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 5741.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc5933.
Copyright Notice
Copyright (c) 2010 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Dolmatov, et al. Standards Track [Page 1]RFC 5933 Use of GOST Signatures in DNSSEC July 2010
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . . 3
2. DNSKEY Resource Records . . . . . . . . . . . . . . . . . . . . 3
2.1. Using a Public Key with Existing Cryptographic
Libraries . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.2. GOST DNSKEY RR Example . . . . . . . . . . . . . . . . . . 4
3. RRSIG Resource Records . . . . . . . . . . . . . . . . . . . . 4
3.1. RRSIG RR Example . . . . . . . . . . . . . . . . . . . . . 5
4. DS Resource Records . . . . . . . . . . . . . . . . . . . . . . 5
4.1. DS RR Example . . . . . . . . . . . . . . . . . . . . . . . 5
5. Deployment Considerations . . . . . . . . . . . . . . . . . . . 6
5.1. Key Sizes . . . . . . . . . . . . . . . . . . . . . . . . . 6
5.2. Signature Sizes . . . . . . . . . . . . . . . . . . . . . . 6
5.3. Digest Sizes . . . . . . . . . . . . . . . . . . . . . . . 6
6. Implementation Considerations . . . . . . . . . . . . . . . . . 6
6.1. Support for GOST Signatures . . . . . . . . . . . . . . . . 6
6.2. Support for NSEC3 Denial of Existence . . . . . . . . . . . 6
7. Security Considerations . . . . . . . . . . . . . . . . . . . . 6
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 7
9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . 7
10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 7
10.1. Normative References . . . . . . . . . . . . . . . . . . . 7
10.2. Informative References . . . . . . . . . . . . . . . . . . 8
1. Introduction
The Domain Name System (DNS) is the global hierarchical distributed
database for Internet Naming. The DNS has been extended to use
cryptographic keys and digital signatures for the verification of the
authenticity and integrity of its data. RFC 4033 [RFC4033], RFC 4034
[RFC4034], and RFC 4035 [RFC4035] describe these DNS Security
Extensions, called DNSSEC.
RFC 4034 describes how to store DNSKEY and RRSIG resource records,
and specifies a list of cryptographic algorithms to use. This
document extends that list with the signature and hash algorithms
GOST R 34.10-2001 ([GOST3410], [RFC5832]) and GOST R 34.11-94
([GOST3411], [RFC5831]), and specifies how to store DNSKEY data and
how to produce RRSIG resource records with these algorithms.
Familiarity with DNSSEC and with GOST signature and hash algorithms
is assumed in this document.
The term "GOST" is not officially defined, but is usually used to
refer to the collection of the Russian cryptographic algorithms
GOST R 34.10-2001 [RFC5832], GOST R 34.11-94 [RFC5831], and
Dolmatov, et al. Standards Track [Page 2]RFC 5933 Use of GOST Signatures in DNSSEC July 2010
GOST 28147-89 [RFC5830]. Since GOST 28147-89 is not used in DNSSEC,
"GOST" will only refer to GOST R 34.10-2001 and GOST R 34.11-94 in
this document.
1.1. Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119].
2. DNSKEY Resource Records
The format of the DNSKEY RR can be found in RFC 4034 [RFC4034].
GOST R 34.10-2001 public keys are stored with the algorithm
number 12.
The wire format of the public key is compatible with RFC 4491
[RFC4491]:
According to [GOST3410] and [RFC5832], a public key is a point on the
elliptic curve Q = (x,y).
The wire representation of a public key MUST contain 64 octets, where
the first 32 octets contain the little-endian representation of x and
the second 32 octets contain the little-endian representation of y.
Corresponding public key parameters are those identified by
id-GostR3410-2001-CryptoPro-A-ParamSet (1.2.643.2.2.35.1) [RFC4357],
and the digest parameters are those identified by
id-GostR3411-94-CryptoProParamSet (1.2.643.2.2.30.1) [RFC4357].
2.1. Using a Public Key with Existing Cryptographic Libraries
At the time of this writing, existing GOST-aware cryptographic
libraries are capable of reading GOST public keys via a generic X509
API if the key is encoded according to RFC 4491 [RFC4491],
Section 2.3.2.
To make this encoding from the wire format of a GOST public key with
the parameters used in this document, prepend the 64 octets of key
data with the following 37-byte sequence:
0x30 0x63 0x30 0x1c 0x06 0x06 0x2a 0x85 0x03 0x02 0x02 0x13 0x30
0x12 0x06 0x07 0x2a 0x85 0x03 0x02 0x02 0x23 0x01 0x06 0x07 0x2a
0x85 0x03 0x02 0x02 0x1e 0x01 0x03 0x43 0x00 0x04 0x40
Dolmatov, et al. Standards Track [Page 3]RFC 5933 Use of GOST Signatures in DNSSEC July 2010
2.2. GOST DNSKEY RR Example
Given a private key with the following value (the value of the
GostAsn1 field is split here into two lines to simplify reading; in
the private key file, it must be in one line):
Private-key-format: v1.2
Algorithm: 12 (ECC-GOST)
GostAsn1: MEUCAQAwHAYGKoUDAgITMBIGByqFAwICIwEGByqFAwICHgEEIgQg/9M
iXtXKg9FDXDN/R9CmVhJDyuzRAIgh4tPwCu4NHIs=
The following DNSKEY RR stores a DNS zone key for example.net:
example.net. 86400 IN DNSKEY 256 3 12 (
aRS/DcPWGQj2wVJydT8EcAVoC0kXn5pDVm2I
MvDDPXeD32dsSKcmq8KNVzigjL4OXZTV+t/6
w4X1gpNrZiC01g==
) ; key id = 59732
3. RRSIG Resource Records
The value of the signature field in the RRSIG RR follows RFC 4490
[RFC4490] and is calculated as follows. The values for the RDATA
fields that precede the signature data are specified in RFC 4034
[RFC4034].
hash = GOSTR3411(data)
where "data" is the wire format data of the resource record set that
is signed, as specified in RFC 4034 [RFC4034].
The hash MUST be calculated with GOST R 34.11-94 parameters
identified by id-GostR3411-94-CryptoProParamSet [RFC4357].
The signature is calculated from the hash according to the
GOST R 34.10-2001 standard, and its wire format is compatible with
RFC 4490 [RFC4490].
Quoting RFC 4490:
"The signature algorithm GOST R 34.10-2001 generates a digital
signature in the form of two 256-bit numbers, r and s. Its octet
string representation consists of 64 octets, where the first
32 octets contain the big-endian representation of s and the second
32 octets contain the big-endian representation of r".
Dolmatov, et al. Standards Track [Page 4]RFC 5933 Use of GOST Signatures in DNSSEC July 2010
3.1. RRSIG RR Example
With the private key from Section 2.2, sign the following RRSet,
consisting of one A record:
www.example.net. 3600 IN A 192.0.2.1
Setting the inception date to 2000-01-01 00:00:00 UTC and the
expiration date to 2030-01-01 00:00:00 UTC, the following signature
RR will be valid:
www.example.net. 3600 IN RRSIG A 12 3 3600 20300101000000 (
20000101000000 59732 example.net.
7vzzz6iLOmvtjs5FjVjSHT8XnRKFY15ki6Kp
kNPkUnS8iIns0Kv4APT+D9ibmHhGri6Sfbyy
zi67+wBbbW/jrA== )
Note: The ECC-GOST signature algorithm uses random data, so the
actual computed signature value will differ between signature
calculations.
4. DS Resource Records
The GOST R 34.11-94 digest algorithm is denoted in DS RRs by the
digest type 3. The wire format of a digest value is compatible with
RFC 4490 [RFC4490], that is, the digest is in little-endian
representation.
The digest MUST always be calculated with GOST R 34.11-94 parameters
identified by id-GostR3411-94-CryptoProParamSet [RFC4357].
4.1. DS RR Example
For Key Signing Key (KSK):
example.net. 86400 DNSKEY 257 3 12 (
LMgXRHzSbIJGn6i16K+sDjaDf/k1o9DbxScO
gEYqYS/rlh2Mf+BRAY3QHPbwoPh2fkDKBroF
SRGR7ZYcx+YIQw==
) ; key id = 40692
The DS RR will be
example.net. 3600 IN DS 40692 12 3 (
22261A8B0E0D799183E35E24E2AD6BB58533CBA7E3B14D659E9CA09B
2071398F )
Dolmatov, et al. Standards Track [Page 5]RFC 5933 Use of GOST Signatures in DNSSEC July 2010
5. Deployment Considerations
5.1. Key Sizes
According to RFC 4357 [RFC4357], the key size of GOST public keys
MUST be 512 bits.
5.2. Signature Sizes
According to the GOST R 34.10-2001 digital signature algorithm
specification ([GOST3410], [RFC5832]), the size of a GOST signature
is 512 bits.
5.3. Digest Sizes
According to GOST R 34.11-94 ([GOST3411], [RFC5831]), the size of a
GOST digest is 256 bits.
6. Implementation Considerations
6.1. Support for GOST Signatures
DNSSEC-aware implementations MAY be able to support RRSIG and DNSKEY
resource records created with the GOST algorithms as defined in this
document.
6.2. Support for NSEC3 Denial of Existence
Any DNSSEC-GOST implementation MUST support both NSEC [RFC4035] and
NSEC3 [RFC5155].
7. Security Considerations
Currently, the cryptographic resistance of the GOST R 34.10-2001
digital signature algorithm is estimated as 2**128 operations of
multiple elliptic curve point computations on prime modulus of order
2**256.
Currently, the cryptographic resistance of the GOST R 34.11-94 hash
algorithm is estimated as 2**128 operations of computations of a step
hash function. (There is a known method to reduce this estimate to
2**105 operations, but it demands padding the colliding message with
1024 random bit blocks each of 256-bit length; thus, it cannot be
used in any practical implementation).
Dolmatov, et al. Standards Track [Page 6]
RFC 5933 Use of GOST Signatures in DNSSEC July 2010
8. IANA Considerations
This document updates the IANA registry "DNS Security Algorithm
Numbers" [RFC4034]. The following entries have been added to the
registry:
Zone Trans.
Value Algorithm Mnemonic Signing Sec. References Status
12 GOST R 34.10-2001 ECC-GOST Y * RFC 5933 OPTIONAL
This document updates the RFC 4034 Digest Types assignment
([RFC4034], Section A.2) by adding the value and status for the
GOST R 34.11-94 algorithm:
Value Algorithm Status
3 GOST R 34.11-94 OPTIONAL
9. Acknowledgments
This document is a minor extension to RFC 4034 [RFC4034]. Also, we
tried to follow the documents RFC 3110 [RFC3110], RFC 4509 [RFC4509],
and RFC 4357 [RFC4357] for consistency. The authors of and
contributors to these documents are gratefully acknowledged for their
hard work.
The following people provided additional feedback, text, and valuable
assistance: Dmitry Burkov, Jaap Akkerhuis, Olafur Gundmundsson,
Jelte Jansen, and Wouter Wijngaards.
10. References
10.1. Normative References
[GOST3410] "Information technology. Cryptographic data security.
Signature and verification processes of [electronic]
digital signature.", GOST R 34.10-2001, Gosudarstvennyi
Standard of Russian Federation, Government Committee of
Russia for Standards, 2001. (In Russian).
[GOST3411] "Information technology. Cryptographic data security.
Hashing function.", GOST R 34.11-94, Gosudarstvennyi
Standard of Russian Federation, Government Committee of
Russia for Standards, 1994. (In Russian).
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
Dolmatov, et al. Standards Track [Page 7]RFC 5933 Use of GOST Signatures in DNSSEC July 2010
[RFC3110] Eastlake 3rd, D., "RSA/SHA-1 SIGs and RSA KEYs in the
Domain Name System (DNS)", RFC 3110, May 2001.
[RFC4033] Arends, R., Austein, R., Larson, M., Massey, D., and S.
Rose, "DNS Security Introduction and Requirements",
RFC 4033, March 2005.
[RFC4034] Arends, R., Austein, R., Larson, M., Massey, D., and S.
Rose, "Resource Records for the DNS Security Extensions",
RFC 4034, March 2005.
[RFC4035] Arends, R., Austein, R., Larson, M., Massey, D., and S.
Rose, "Protocol Modifications for the DNS Security
Extensions", RFC 4035, March 2005.
[RFC4357] Popov, V., Kurepkin, I., and S. Leontiev, "Additional
Cryptographic Algorithms for Use with GOST 28147-89,
GOST R 34.10-94, GOST R 34.10-2001, and GOST R 34.11-94
Algorithms", RFC 4357, January 2006.
[RFC4490] Leontiev, S., Ed. and G. Chudov, Ed., "Using the
GOST 28147-89, GOST R 34.11-94, GOST R 34.10-94, and
GOST R 34.10-2001 Algorithms with Cryptographic Message
Syntax (CMS)", RFC 4490, May 2006.
[RFC4491] Leontiev, S., Ed. and D. Shefanovski, Ed., "Using the
GOST R 34.10-94, GOST R 34.10-2001, and GOST R 34.11-94
Algorithms with the Internet X.509 Public Key
Infrastructure Certificate and CRL Profile", RFC 4491,
May 2006.
[RFC5155] Laurie, B., Sisson, G., Arends, R., and D. Blacka, "DNS
Security (DNSSEC) Hashed Authenticated Denial of
Existence", RFC 5155, March 2008.
10.2. Informative References
[RFC4509] Hardaker, W., "Use of SHA-256 in DNSSEC Delegation Signer
(DS) Resource Records (RRs)", RFC 4509, May 2006.
[RFC5830] Dolmatov, V., Ed., "GOST 28147-89: Encryption,
Decryption, and Message Authentication Code (MAC)
Algorithms", RFC 5830, March 2010.
[RFC5831] Dolmatov, V., Ed., "GOST R 34.11-94: Hash Function
Algorithm", RFC 5831, March 2010.
Dolmatov, et al. Standards Track [Page 8]RFC 5933 Use of GOST Signatures in DNSSEC July 2010
[RFC5832] Dolmatov, V., Ed., "GOST R 34.10-2001: Digital Signature
Algorithm", RFC 5832, March 2010.
Authors' Addresses
Vasily Dolmatov (editor)
Cryptocom Ltd.
14/2, Kedrova St.
Moscow, 117218
Russian Federation
Phone: +7 499 124 6226
EMail: dol@cryptocom.ru
Artem Chuprina
Cryptocom Ltd.
14/2, Kedrova St.
Moscow, 117218
Russian Federation
Phone: +7 499 124 6226
EMail: ran@cryptocom.ru
Igor Ustinov
Cryptocom Ltd.
14/2, Kedrova St.
Moscow, 117218
Russian Federation
Phone: +7 499 124 6226
EMail: igus@cryptocom.ru
Dolmatov, et al. Standards Track [Page 9]
